Sanding block

ABSTRACT

A sanding block for a continuous loop type sanding belt, comprising a basic rectangular block with an end block element which is longitudinally adjustable by means of screw jack elements to clamp tightly inside the sanding belt. The screw jack elements are readily accessible and are operable without tools.

United States Patent Inventor Stuart F. Bowen 5626 Vale Way, San Diego, Calif. 92115 Appl. No. 15,047

Filed Feb. 27, 1970 Patented Aug. 31, 1971 SANDING BLOCK 8 Claims, 4 Drawing Figs.

US. Cl 51/372, 5 1/391 Int. Cl 824d 15/02 Field oi Search 51/391493,

372, l70 EB [56] References Cited UNITED STATES PATENTS 2,621,453 12/1952 Oren 51/170 EB 3,063,208 11/1962 Bell 51/39] X 3,106,806 10/1963 Hutchins 51/391 X Primary ExaminerDonald G. Kelly Attorney-Carl R. Brown ABSTRACT: A sanding block for a continuous loop type sanding belt, comprising a basic rectangular block with an end block element which is longitudinally adjustable by means of screw jack elements to clamp tightly inside the sanding belt. The screw jack elements are readily accessible and are operable without tools.

PATENTEH M1831 I974 INVENTOR. STUART F. BOWEN WQ M ATTORNEY Fig.4

Sanding blocks for use with continuous loop type sanding belts are well known and usually have sliding or expanding portions actuated by cams, wedges, linkages and the like, which require tools for their operation or are inconvenient to adjust when it is necessary to change a sanding belt. Spring expanded types tend to compress in use and cause the sanding belt to loosen. Cam and wedge types do not usually have an equal clamping force across their width, resulting in uneven belt tension.

It is thus desirable to have a sanding block with simple, manually operable clamping means which provides even belt tension and is quickly adjustable.

SUMMARY OF THE INVENTION The sanding block described herein comprises a basic, generally rectangular block of wood or similar low cost material of suitable solidity, with an adjustable end portion forming a continuation of the basic block. The end portion is coupled to the basic block by a pair of screw jack elements actuated by large manually operable nuts accessible at opposite sides of the block. Threaded studs of the jack elements are fixed into the end portion and slide in sleeves inset in the basic block, the nuts bearing on flanged ends of the sleeves for smooth rotation as-pressure' is applied. A few turns of the nuts are sufficient to loosen and tighten the block assembly for changing the sanding belt. The adjustable end portion, which is a small part of the complete block, may be of wood, or can be conveniently molded from plastic material, the block structure being very simple and economical to manufacture.

An object of this invention, therefore, is to provide a new and improved sanding block for a continuous loop sanding belt.

Another object of this invention is to provide a sanding block which is manually adjustable by simple, accessible means for insertion into and clamping in a sanding belt.

A further object of this invention is to provide a sanding block which exerts even tension on the sanding belt.

Another object of this invention is to provide a sanding block which has very few parts and can be made from low cost materials.

Other objects and many advantages of this invention will become more apparent upon a reading of the following detailed description and an examination of the drawings wherein:

BRIEF DESCRIPTION OF THE DRAWING assembled sanding block DESCRIPTION OF THE PREFERRED EMBODIMENT The structure comprises a basic block of rectangular configuration and an end block 12 of similar cross section forming an adjustable end portion of the block. As shown, the block 10 has flat opposite faces 14 and 16 and a square outer end 18, but could be contoured for special applications. The outer end 20 of end block 12 is rounded to facilitate the sanding of curved surfaces. The square end 18 of block 10 is a useful sanding surface with sharp right angle edges 17 to effectively sand corners, for example. Belt 22 is a continuous loop type which is readily available in standard sizes with a variety of surfaces for rough sanding, finishing and similar operations. As the belt wears with use at, for example, the edges 117 of the square end 18, or the belt tends to fracture due to the sharp edges, the belt may be loosened, rotated and retensioned to brin unused portions of the belt into play.

F xed in the end block 12 and projecting from its inner face 24, are two studs 26 in spaced parallel relation. The end block has noncircular sockets 28, shown as substantially D shaped, the studs having a similar cross section and being slightly tapered for a nonrotating drive fit into the block. Sleeves 32 are spaced to receive the screw threaded portions 38 of studs 26 with a smooth sliding fit. On each threaded stud portion is a large nut 40 with flutes 42 for ease of manual rotation. When the nuts are rotated in the proper direction the end block 12 is forced outwardly from block 10, the nuts bearing on flanges 34 which reduces friction and facilitates operation.

On each side of block I0 is a longitudinal recess or groove 44 to provide finger grips for secure holding of the block. Each groove 44 extends to inner end face 36 and is continued as a short groove 46 in the side of end block 12. The recesses thus formed provide access to nuts 40, without the need for the nuts to project beyond the sides of the block.

The block 10 is preferably of wood for economy and ease of manufacture and to provide solidity with reasonable weight, although other materials could be used. Each block 12 is shown as being of plastic material, since the small element with the sockets and special shaping lends itself well to molding. Sleeves 32 are of plastic with suitable wearing qualities to provide bearings for nuts 40 and allow the studs to slide smoothly.

With the nuts 40 backed off adjacent end block 12, the collapsed block assembly is easily inserted into the sanding belt. Both nuts are then turned together to expand the blocks and clamp tightly into the belt. The rounded end 20 allows the end block to seat into the belt without tearing as the assembly is expanded.

Having described my invention, I now claim:

1. A sanding block for a continuous loop sanding belt comprising,

an elongated basic block and a substantially smaller end block in end to end coplanar alignment,

a pair of threaded studs fixed in and extending from one of said blocks in spaced parallel relation, the other block having sockets for slidably receiving said studs,

and manually rotatable nuts on said studs between the confronting faces of said blocks, said nuts being accessible at the sides of the blocks.

2. A sanding block according to Claim 1, wherein said sockets have sleeves therein, said sleeves having flanges against which said nuts bear.

3. A sanding block according to Claim 1, wherein said nuts are contained within the width of said blocks, the blocks having recessed side portions adjacent said nuts for access thereto.

4. A sanding block according to Claim ll, wherein said end block has a smoothly rounded outer end.

5. A sanding block according to Claim 1, wherein said studs are nonrotatably fixed in said end block, said sockets extending longitudinally into said basic block from the inner end thereof confronting the end block.

6. A sanding block according to Claim 5, and including sleeves in said sockets, said sleeves having flanges seated on said inner end of the block, providing bearings for said nuts.

7. A sanding block according to Claim 6, wherein said end block has a smoothly rounded outer end.

8. A sanding block according to Claim 7, wherein said basic block has longitudinal grooves in the sides thereof extending to the inner end adjacent said nuts, said end block having grooves in the sides thereof forming extensions of said first mentioned grooves and providing access to the nuts. 

1. A sanding block for a continuous loop sanding belt comprising, an elongated basic block and a substantially smaller end block in end to end coplanar alignment, a pair of threaded studs fixed in and extending from one of said blocks in spaced parallel relation, the other block having sockets for slidably receiving said studs, and manually rotatable nuts on said studs between the confronting faces of said blocks, said nuts being accessible at the sides of the blocks.
 2. A sanding block according to Claim 1, wherein said sockets have sleeves therein, said sleeves having flanges against which said nuts bear.
 3. A sanding block according to Claim 1, wherein said nuts are contained within the width of said blocks, the blocks having recessed side portions adjacent said nuts for access thereto.
 4. A sanding block according to Claim 1, wherein said end block has a smoothly rounded outer end.
 5. A sanding block according to Claim 1, wherein said studs are nonrotatably fixed in said end block, said sockets extending longitudinally into said basic block from the inner end thereof confronting the end block.
 6. A sanding block according to Claim 5, and including sleeves in said sockets, said sleeves having flanges seated on said inner end of the block, providing bearings for said nuts.
 7. A sanding block according to Claim 6, wherein said end block has a smoothly rounded outer end.
 8. A sanding block according to Claim 7, wherein said basic block has longitudinal grooves in the sides thereof extending to the inner end adjacent said nuts, said end block having grooves in the sides thereof forming extensions of said first mentioned grooves and providing access to the nuts. 